Taking account of the force arising from the relative wind velocity between the cup and the wind, the differential equation of rotation of cup assembly was formulated. Dynamic responses of cup anemometers to the stepwise and sinusoidal wind changes and to turbulent fluctuations of wind speed were numerically examined. And the damping rate of amplitude and the phase lag in measuring fluctuating wind, and the over-estimation factor in measuring mean wind speed were estimated. These characteristics of the cup anemometer may be expressed according to two constants, which are the calibration constant and the response distance of anemometer. The errors in measured mean wind speed are presented for typical turbulent winds of "wind over sea" and "wind over land".
The diurnal changes of wind, air temperature, and water vapor profiles near the ground have been investigated by integrating numerically the diff erential equations of momentum, heat and vapor transfers. The equation for change of air temperature includes the long-wave radiative heat transfer. Equality of the diffusivities for momentum, heat and vapor transfers is assumed. Profiles obtained deviate from the theoretical profiles which exclude the long-wave radiative heat transfer, and assume the steady state. In the stable case, the deviation of estimated wind velocity is relatively small and that of air temperature is somewhat larger, and the largest dis- crepancy is seen in the profile of water vapor. In unstable cases, the so-called constant-flux layer is at the heights of several tens of meters, but in stable cases, it is about several meters high. In the daytime at the height of several centimeters, there is a layer of intense heating due to radiative flux divergence. It appears that such excess rate of heating might yield the heat energy of convective mixing. In the nighttime, radiation fog started to form in a layer about 0.1 to 1m high from the surface, and the layer, after spreading slowly upwards, finally disappeared after sunrise.
For the purpose of discussing the seasonal variation of total ozone amount, the authors assume that the observed total amount of ozone consists of two components. One corresponds to the photochemical equilibrium, the other will be related to the effects of atmospheric circulations. In this paper the former will be called Effect A and the latter Effect B. The obtained results indicate that Effect B is most active in winter and that its activity increases with latitude and moreover that its hemispheric pattern is similar to that of ultra-long waves. It follows that Effect B has correlation with the activity of the transport of ozone. On the other hand, the magnitude of Effect A is of the same order as Effect B. This result suggests that the contribution of the photochemical effect to the annual variation of ozone seems to be greater than the one expected from the dry theory of ozone. Consequently the wet theory is more acceptable than the dry one. As mentioned above, the total amount of ozone is assumed to be the sum of two components. Therefore the annual variations of total ozone amoount at a latitude vary according to the magnitude of Effect B because that of Effect A is defined as a function of latidude. In other words the larger
The electric charge on freezing water droplets with sizes of 20 to 100μ was measured in a state of free fall at temperatures of -25°C to -40°C. As a result of the measurements, it was noted that the number of negatively charged droplets was greater than that of positively charged ones. It was also found that the mean value of the negative charge was much greater than that of the positive charge in a temperature region colder than -35°C, especially at water homogeneous nucleation temperature; -40°C. This result suggests that the freezing water droplets obtained a negative charge by some mecha- nism, when they were frozen very rapidly. However it appears that the electrification mechanism of the freezing water droplets around -40°C was different from that presented by Mason and Maybank, or Stott and Hutchinson.